Sura al-Shūrā 42:51

وَمَا كَانَ لِبَشَرٍ أَن يُكَلِّمَهُ ٱللَّـهُ إِلَّا وَحْيًا أَوْ مِن وَرَآئِ حِجَابٍ أَوْ يُرْسِلَ رَسُولًا فَيُوحِىَ بِإِذْنِهِۦ مَا يَشَآءُ إِنَّهُۥ عَلِىٌّ حَكِيمٌ

wa-mā kāna li-basharin an yukallimahu allāhu illā waḥyan aw min warāi ḥijābin aw yursila rasūlan fa-yūḥiya bi-idhnihi mā yashāʾu innahu ʿaliyyun ḥakīmun

It is not fitting for a man that Allah should speak to him except by inspiration, or from behind a veil, or by the sending of a messenger to reveal, with Allah's permission, what Allah wills: for He is Most High, Most Wise.